PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Scientists do glass a solid -- with new theory on how it transitions from a liquid

2014-11-24
(Press-News.org) How does glass transition from a liquid to its familiar solid state? How does this common material transport heat and sound? And what microscopic changes occur when a glass gains rigidity as it cools?

A team of researchers at NYU's Center for Soft Matter Research offers a theoretical explanation for these processes in Proceedings of the National Academy of Sciences.

Our understanding of glasses as they change state is relatively limited. This is because, unlike other materials such as metals, their constituent particles--which can be as small as a billionth of a meter in size--are in a disorganized, rather than orderly, arrangement. Understanding what in these disordered arrangements decides if the material is liquid or solid remains a long-lasting challenge of physics and chemistry.

The simplest examples of glasses are colloidal suspensions, which behave essentially as hard spheres. Beyond their conceptual interest, they also matter to scientists because they are the basis for an array of consumer products. For instance, colloidal dispersions comprise such everyday items as paint, milk, gelatin, glass, and porcelain. Moreover, understanding how they evolve from liquids to solids is of concern to medical researchers--for example, the clotting of blood.

Colloids form a liquid at small density, but become solid when the density is increased beyond some threshold. At that point, crowding effects become important: particles are prisoners of the cage formed by their neighbors. Although they can still wiggle somewhat within their cage, they cannot escape far, forbidding flow. Why the assembly of cages can resist the wiggling of particles in the solid phase is a long-standing debate in the field. Explanations have been proposed in very abstract models, but a simple physical picture of what is going on was lacking.

In their theoretical work, spurred by laboratory observations of colloidal glasses, the researchers propose to use 19th-century concepts developed by Maxwell, the founder of electromagnetism, to study the stability of mechanical structures. Thus concepts widely used in architecture and engineering are now applied at a microscopic level in colloidal glasses. Based on these ideas, the authors developed a theory of the emergence of rigidity.

A curious outcome of their work is the prediction that the wiggling motion of particles in their cage is collective: particles dance in a very coordinated way. The structure of the material is predicted to be such that the dance has the largest amplitude it could possibly have without destroying the solid.

The authors show that this coordinated dance is quantitatively affected by the presence of weak spots in the materials. The description leads to various predictions on the dynamics of the particles, as well as the elastic response of the material and the ability to transport heat in molecular glasses.

INFORMATION:

The study's authors included Carolina Brito of the Universidade Federal do Rio Grande do Sul, Brazil as well as the following researchers in the Wyart group at NYU's Center for Soft Matter Research: Eric DeGiuli, a post-doctoral fellow, Edan Lerner, a post-doctoral fellow at the time of the study and now an assistant professor at the University of Amsterdam, and Matthieu Wyart, an associate professor in NYU's Department of Physics.

This work is supported by grants from the National Science Foundation (1236378; 1105387) as well as the NSF's MRSEC Program (DMR-0820341)



ELSE PRESS RELEASES FROM THIS DATE:

Threats of terrorism perceived differently depending on identification within a group

2014-11-24
People who see their group as more homogenous - for instance, the more one thinks Americans are similar to each other - are less likely to be influenced by external terrorist threat alerts, according to research from NYU's Steinhardt School of Culture, Education, and Human Development. "Among people who viewed their group to be homogeneous, external threat did not translate to higher perceived threat, and they did not influence beliefs about the legitimacy of the U.S. military intervention in Iraq," said study author Rezarta Bilali, assistant professor of psychology and ...

Teens prescribed anxiety, sleep medications likelier to illegally abuse them later

2014-11-24
ANN ARBOR--The medical community may be inadvertently creating a new generation of illegal, recreational drug users by prescribing anti-anxiety or sleep medications to teenagers, say University of Michigan researchers. Teens prescribed anxiety or sleep medications are up to 12 times more likely to abuse those drugs than those who had never had a prescription, either by using someone else's prescription pills or to get high or experiment, according to a study from the U-M School of Nursing. Nearly 9 percent of the 2,745 adolescent study participants had received ...

ASU, IBM move ultrafast, low-cost DNA sequencing technology a step closer to reality

ASU, IBM move ultrafast, low-cost DNA sequencing technology a step closer to reality
2014-11-24
A team of scientists from Arizona State University's Biodesign Institute and IBM's T.J. Watson Research Center have developed a prototype DNA reader that could make whole genome profiling an everyday practice in medicine. "Our goal is to put cheap, simple and powerful DNA and protein diagnostic devices into every single doctor's office," said Stuart Lindsay, an ASU physics professor and director of Biodesign's Center for Single Molecule Biophysics. Such technology could help usher in the age of personalized medicine, where information from an individual's complete DNA ...

Scientists solve reptile mysteries with landmark study on the evolution of turtles

Scientists solve reptile mysteries with landmark study on the evolution of turtles
2014-11-24
SAN FRANCISCO (November 24, 2014) --A team of scientists, including researchers from the California Academy of Sciences, has reconstructed a detailed "tree of life" for turtles. The specifics of how turtles are related--to one another, to other reptiles, and even to dinosaurs--have been hotly debated for decades. Next generation sequencing technologies in Academy labs have generated unprecedented amounts of genetic information for a thrilling new look at turtles' evolutionary history. These high-tech lab methods revolutionize the way scientists explore species origins and ...

Educating on sickle cell risk

2014-11-24
Members of the public in sub-Saharan Africa who are carriers of the hereditary disease sickle cell disease must be educated aggressively through public health campaigns to raise awareness of the risks of parenting offspring with the disease if their partner is also a carrier, according to research published in the International Journal of Medical Engineering and Informatics. There are many physical and emotional public health components of sickle cell disease, explains William Ebomoyi of the Department of Health Studies College of Health Sciences, Chicago State University, ...

End to end 5G for super, superfast mobile

2014-11-24
A collaboration between NEC Electronics Samsung and several academic centres in China and Iran, is investigating how software-defined cellular networking might be used to give smart phone users the next generation of super-superfast broadband, 5G. They provide details in the International Journal of Communication Networks and Distributed Systems. Currently, the fourth generation of mobile phone connection technology, 4G, in as far as it has been adopted provides broadband-type connectivity for enabled devices such as smart phones, tablet computers, laptops and other gadgets ...

Fiddler on the roof?

Fiddler on the roof?
2014-11-24
WOODS HOLE, Mass.--David Johnson was standing in a salt marsh on the northern Massachusetts coast when he saw a fiddler crab, Uca pugnax, nearly 50 miles north of its supposed natural range. The migration north of this charismatic crab with the big, waving claw may be yet another sign of climate change. Johnson, then a scientist at the Marine Biological Laboratory (MBL) Ecosystems Center, has published his observations in the Journal of Crustacean Biology. The fiddler crab is an attention-getting crustacean; the males have an oversized claw that they use to attract a ...

How the hummingbird achieves its aerobatic feats

How the hummingbird achieves its aerobatic feats
2014-11-24
VIDEO: The most detailed aerodynamic simulation of hummingbird flight conducted to date demonstrates that it achieves its aerobatic abilities through a unique set of aerodynamic forces more closely aligned to those... Click here for more information. The sight of a tiny hummingbird hovering in front of a flower and then darting to another with lightning speed amazes and delights. But it also leaves watchers with a persistent question: How do they do it? Now, the most detailed, ...

The Lancet: Universal health coverage for US military veterans within reach, but many still lack coverage

2014-11-24
Over a million US military veterans lacked healthcare coverage in 2012, according to new estimates published in The Lancet. While many people believe that all veterans are covered by the Veterans Affairs health care system, less than half (8.9 million) of the 22 million veterans in the US are covered by VA health benefits, and most veterans are covered by private health insurance. Uninsured veterans are more likely to be young, single, African American, and veterans of Iraq and Afghanistan. However, the authors of this viewpoint estimate that universal health coverage ...

Declining loneliness among American teenagers

2014-11-24
There has been a growing concern that modern society is increasingly lonely. In 2006, a New York Times article "The Lonely American Just Got a Bit Lonelier" highlighted research that shows a decline in social engagement--people are less likely to join clubs, have fewer close friends, and are less likely to perceive others as trustworthy. However, studies have also shown an increase in extraversion and self-esteem, which suggests loneliness is decreasing. In an effort to study the societal trend of loneliness, researchers from the University of Queensland and Griffith ...

LAST 30 PRESS RELEASES:

Sacituzumab govitecan plus platinum-based chemotherapy in breast, bladder, and lung carcinomas

Global study unveils "problematic" use of porn

Newly discovered protein prevents DNA triplication

Less ice in the arctic ocean has complex effects on marine ecosystems and ocean productivity

Antarctica’s coasts are becoming less icy

New research shows migrating animals learn by experience

Modeling the origins of life: New evidence for an “RNA World”

Scientists put forth a smarter way to protect a smarter grid

An evolutionary mystery 125 million years in the making

Data science approach to identifying thermal conductivity-related structural factors in amorphous materials

Deciphering the male breast cancer genome

Detection of suicide-related emergencies among children using real-world clinical data: A free webinar from the Brain & Behavior Research Foundation

Editor-in-Chief of Sustainability and Climate Change Madhavi Venkatesan named USA TODAY Woman of the Year for Massachusetts for leading plastic bottle ban efforts

Tests show high-temperature superconducting magnets are ready for fusion

Zika vaccine safe, effective when administered during pregnancy

Firearm ownership is correlated with elevated lead levels in children, study finds

Role of African women and young people in agricultural service provision investigated in new CABI-led study

26th International Conference of the Redox Medicine Society Set for June 2024 in Paris, France

Geologists explore the hidden history of Colorado’s Spanish Peaks

Webb unlocks secrets of one of the most distant galaxies ever seen

3D-printed skin closes wounds and contains hair follicle precursors

Discovered a RNA molecule that helps prevent DNA replication errors

Small and overlooked: Amount of repetitive DNA in blood hints at cancer early

Study determines the original orientations of rocks drilled on Mars

Illinois study: Supporting disease-challenged broiler chickens through nutrition

Communities severed by roads and traffic experience a larger number of collisions in New York City

Study shows new class of antivirals that works against SARS-CoV-2

Cost of direct air carbon capture to remain higher than hoped

Unraveling the mystery of chiton visual systems

Case Western Reserve University-led research team discovers new method to test for oral cancer

[Press-News.org] Scientists do glass a solid -- with new theory on how it transitions from a liquid